#define _CRT_SECURE_NO_WARNINGS 1
#pragma warning(disable:6031)

#include<stdio.h>
#include<string.h>
#include<assert.h>

size_t my_strlen(char* str)
{
	assert(*str);
	size_t num = 0;
	while (*str++)
	{
		num++;
	}
	return num;
}

int main()
{
	char arr[10] = "v b n";
	printf("%u\n", my_strlen(arr));
	return 0;
}